Duke Eric of Friuli

  General Notes:

Eric (also Heirichus or Ehericus;[1] died 799) was the Duke of Friuli (dux Foroiulensis) from 789 to his death. He was the eldest son of Gerold of Vinzgouw and by the marriage of his sister Hildegard the brother-in-law of Charlemagne.

Most of Eric's tenure was occupied by the job of subduing the Avars. In this he was accompanied by Pepin of Italy and his own father, the margrave of Avaria. In 791, he and Pepin marched a Lombard army into the Drava valley and ravaged Pannonia, while Charlemagne marched along the Danube into Avar territory. Charlemagne left the campaigning to deal with a Saxon revolt in 792. Pepin and Eric continued, however, to assault the Avars' ring-shaped strongholds. The great Ring of the Avars, their capital fortress, was taken twice. The booty was sent to Charlemagne in Aachen and redistributed to all his followers and even to foreign rulers, including King Offa of Mercia.
http://en.wikipedia.org/wiki/Eric_of_Friuli